## Reading from a File
To start reading a file, you first need to open it in the appropriate mode. Here's how you can open and read from a file:
``` python
file = open("greetings.txt", "r")
print(file.read()) # Output:
# Hello, world!
# Salut!
# Hola!
file.close()
```

## Reading Specific Characters
You can also read a specific number of characters by passing a numeric argument to the read method:
``` python
file = open("greetings.txt", "r")
print(file.read(10))  # Output: Hello, wor
file.close()
```

## Reading Line by Line
To read a file line by line, you can use a **loop** along with the `readline()` or `readlines()` methods. The `readline()` method returns a string for each line, while readlines() returns a **list** of all lines:
``` python
file = open("greetings.txt", "r") # ['Hello, world!\n', 'Salut!\n']
print(file.readline())  # Output: Hello, world!
print(file.readline())  # Output: Salut!
file.close()
```
For more efficient line-by-line reading without loading the entire file into memory, use a `for` loop with `readlines()`:
``` python
file = open("greetings.txt", "r")
for line in file.readlines():
    print(line, end="")  # The `end=""` argument prevents adding extra line breaks
# Output:
# Hello, world!
# Salut!
# Hola!
file.close()
```

## Writing to a File
To write data to a file, you should open it in write mode ('w'). Only strings can be passed to the write() method.
``` python
file = open("greetings.txt", "w")
file.write("Bonjour!")
file.close()
```
> Note
>
> The writing mode overwrites the existing file content.

In this case, any existing data in "greetings.txt" will be replaced with "Bonjour!"

Choose the right statement for the `'r'` mode:

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Python Advanced Concepts

Reading and Writing Files: Handling Text and Data Efficiently

Reading from a File

Reading Specific Characters

Reading Line by Line

Writing to a File